// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "net/socket/tcp_server_socket.h"

#include <utility>

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/logging.h"
#include "net/base/net_errors.h"
#include "net/socket/tcp_client_socket.h"

namespace net {

TCPServerSocket::TCPServerSocket(NetLog* net_log, const NetLog::Source& source)
    : socket_(nullptr, net_log, source)
    , pending_accept_(false)
{
}

TCPServerSocket::~TCPServerSocket()
{
}

int TCPServerSocket::Listen(const IPEndPoint& address, int backlog)
{
    int result = socket_.Open(address.GetFamily());
    if (result != OK)
        return result;

    result = socket_.SetDefaultOptionsForServer();
    if (result != OK) {
        socket_.Close();
        return result;
    }

    result = socket_.Bind(address);
    if (result != OK) {
        socket_.Close();
        return result;
    }

    result = socket_.Listen(backlog);
    if (result != OK) {
        socket_.Close();
        return result;
    }

    return OK;
}

int TCPServerSocket::GetLocalAddress(IPEndPoint* address) const
{
    return socket_.GetLocalAddress(address);
}

int TCPServerSocket::Accept(std::unique_ptr<StreamSocket>* socket,
    const CompletionCallback& callback)
{
    DCHECK(socket);
    DCHECK(!callback.is_null());

    if (pending_accept_) {
        NOTREACHED();
        return ERR_UNEXPECTED;
    }

    // It is safe to use base::Unretained(this). |socket_| is owned by this class,
    // and the callback won't be run after |socket_| is destroyed.
    CompletionCallback accept_callback = base::Bind(&TCPServerSocket::OnAcceptCompleted, base::Unretained(this),
        socket, callback);
    int result = socket_.Accept(&accepted_socket_, &accepted_address_,
        accept_callback);
    if (result != ERR_IO_PENDING) {
        // |accept_callback| won't be called so we need to run
        // ConvertAcceptedSocket() ourselves in order to do the conversion from
        // |accepted_socket_| to |socket|.
        result = ConvertAcceptedSocket(result, socket);
    } else {
        pending_accept_ = true;
    }

    return result;
}

void TCPServerSocket::DetachFromThread()
{
    socket_.DetachFromThread();
}

int TCPServerSocket::ConvertAcceptedSocket(
    int result,
    std::unique_ptr<StreamSocket>* output_accepted_socket)
{
    // Make sure the TCPSocket object is destroyed in any case.
    std::unique_ptr<TCPSocket> temp_accepted_socket(std::move(accepted_socket_));
    if (result != OK)
        return result;

    output_accepted_socket->reset(
        new TCPClientSocket(std::move(temp_accepted_socket), accepted_address_));

    return OK;
}

void TCPServerSocket::OnAcceptCompleted(
    std::unique_ptr<StreamSocket>* output_accepted_socket,
    const CompletionCallback& forward_callback,
    int result)
{
    result = ConvertAcceptedSocket(result, output_accepted_socket);
    pending_accept_ = false;
    forward_callback.Run(result);
}

} // namespace net
